The present invention relates to the technical field of an image processing method. More particularly, the present invention mainly relates to an image processing method that is capable of performing favorable image verification and image processing with least decrease of work efficiency even when each fram (image) clipping is not appropriate, namely, a frame clipping error (a clipping error of a frame area or frame position) occurs, in the image processing for setting an image processing condition by reading an image on a film photoelectrically.
Heretofore, the images recorded on photographic films such as negatives and reversals (which are hereunder referred to simply as xe2x80x9cfilmsxe2x80x9d) have been commonly printed on light-sensitive materials (photographic paper) by means of direct (analog) exposure in which the light-sensitive materials are exposed by projection light through the films.
A new technology has recently been introduced and this is a printer that relies upon digital exposure. Briefly, the image recorded on a film is read photoelectrically, converted to digital signals and subjected to various image processing operations to produce image data for recording purposes; recording light that has been modulated in accordance with the image data is used to scan and expose a light-sensitive material to record an image (latent image), which is subsequently developed to produce a print (photograph). The printer operating on this principle has been commercialized as a digital photoprinter.
The digital photoprinter basically comprises a scanner (image reading apparatus) for reading an image recorded on the film photoelectrically by projecting a reading light to a film and reading its projection light, an image processing apparatus for carrying out a predetermined image processing on an input image data read by the scanner so as to obtain an output image data for image recording, that is, exposure condition, a printer (image recording apparatus) for recording the image as a latent image by exposing a light-sensitive material by, for example, scanning with light beam corresponding to the output image data outputted from the image processing apparatus, and a processor (developing apparatus) for carrying out development processing on the light-sensitive material exposed by the printer so as to produce a finished print in which the image is reproduced.
In the digital photoprinter having such features, images are handled as digital image data so that image processing can be performed by image data processing. Therefore, correction of washed-out highlights or dull shadows caused by photographing with backlight, an electronic flash or the like, sharpness processing, correction of color failures, density failures or the like, correction of under-exposure or over-exposure, and correction of insufficient marginal lumination or the like are favorably performed to produce a high quality print which has never been realized by a conventional direct exposure.
The photoprinter reads the image record on the film photoelectrically utilizing a CCD sensor or the like for the purpose of stably outputting an appropriately-finished print to obtain input image data and, thereafter, based on the thus obtained input image data, determines an image processing condition (insertion quantity of a color filter or the like in the case of direct exposure) on a frame (image) basis.
Reading of the image, for example, in an apparatus employing an area sensor, is performed by illuminating a whole area of individual frames one after another with a reading light while the film is intermittently transported so as to hold individual frames in registry with a predetermined reading position one after another. In an apparatus employing a line sensor, the whole area of the film read by slit scanning with the reading light while the film is continuously transported and, then, the image of each frame is read by detecting each frame from the obtained image data.
However, an opportunity may occur in which an image area of each frame (clipping area of each image) is not appropriate, namely, the frame clipping error (detection failure of the frame) is brought about depending on transport accuracy of the film, a condition of the image (particularly, under-exposure image) or the like. Moreover, this frame clipping error can be confirmed only by representing the image on a display.
When the frame clipping error occurred, image processing condition must be set again in such a way that, in the apparatus employing the area sensor, the image is read again while, in the apparatus employing the line sensor, the image area is detected again, thereby setting the image processing condition anew. For this reason, when the frame clipping error occurs, work efficiency or production efficiency of the finished prints is decreased and complexity of work sequence is brought about.
Particularly, in the apparatus employing the line sensor, in order to perform image processing more favorably, a system is known to set the respective image processing condition of each frame by using image data of all frames recorded on a film. However, in this system, if the clipping error of one frame occurs, the image processing conditions of all frames must be set again, thereby bringing about decrease of work efficiency to a great extent.
An object, therefore, of the present invention is to solve the problems in the above-described prior art and to provide an image processing method capable of preventing the decrease of work or production efficiency or keeping it to a minimum, even if a frame clipping error occurs and outputting an appropriate image stably and consistently in a photoprinter.
In order to achieve the above-described object, the present invention provides an image processing method of setting an image processing condition of an image using image data of the image obtained by photoelectrically reading an original recorded continuously with a plurality of images, comprising the steps of:
setting the image processing condition of the image using either image data of an image clipping area corresponding to the image or extended image data which is image data of an extended image area that is wider than the image clipping area in a direction in which the images are continuously recorded;
representing an image obtained by processing the extended image data in accordance with the image processing condition and the image clipping area or only an image within the image clipping area obtained by processing the extended image data in accordance with the image processing condition;
judging whether the represented image clipping area is appropriate or not; and
modifying the image clipping area in accordance with a result of the judging.
Here, preferably, in addition to the image processing condition set as a first image processing condition using the extended image data, a second image processing condition is set using the image data of the image clipping area and wherein the extended image data is processed using the first image processing condition and the second image processing condition.
Moreover, preferably, the first image processing condition corresponds to processing of a local area of the image, and wherein the second image processing condition corresponds to processing of a whole area of the image.
It is preferable that processing of the local area of the image is processing using an area mask, and wherein processing of the whole area of the image is processing of at least one of density and color balance.
Preferably, a ratio of the extended image data to the image clipping area is allowed to be changeable from one image to one image such that when a clipping accuracy of the image clipping area becomes lower, the ratio becomes larger.